Semiconductor Energy Laboratory Co., Ltd.

Kyoko Yoshioka

Junichi Koezuka

Shinya Sasagawa

Yuichi Sato

Yuhei Sato

Naoto Yamade

Shinji Ohno

Mari Terashima

A miniaturized semiconductor device in which an increase in power consumption is suppressed and a method for manufacturing the semiconductor device are provided. A highly reliable semiconductor device having stable electric characteristics and a method for manufacturing the semiconductor device are provided. An oxide semiconductor film is irradiated with ions accelerated by an electric field in order to reduce the average surface roughness of a surface of the oxide semiconductor film. Consequently, an increase in the leakage current and power consumption of a transistor can be suppressed. Moreover, by performing heat treatment so that the oxide semiconductor film includes a crystal having a c-axis substantially perpendicular to the surface of the oxide semiconductor film, a change in electric characteristics of the oxide semiconductor film due to irradiation with visible light or ultraviolet light can be suppressed.

Semiconductor device and method for manufacturing the same

A highly reliable semiconductor device which is formed using an oxide semiconductor and has stable electric characteristics is provided. A semiconductor device which includes an amorphous oxide semiconductor layer including a region containing oxygen in a proportion higher than that in the stoichiometric composition, and an aluminum oxide film provided over the amorphous oxide semiconductor layer is provided. The amorphous oxide semiconductor layer is formed as follows: oxygen implantation treatment is performed on a crystalline or amorphous oxide semiconductor layer which has been subjected to dehydration or dehydrogenation treatment, and then thermal treatment is performed on the oxide semiconductor layer provided with an aluminum oxide film at a temperature lower than or equal to 450&#xb0; C.

Semiconductor device

Growing community of inventors

Kanagawa, Japan

Kyoko Yoshioka